By the experiments of highspeed milling of TA15 titanium (Ti) alloy, the law of influence of the cutting parameters on surface morphology and microstructure was investigated. A method was put forward of the surface contour arithmetic average deviation acting as the evaluation parameters of surface roughness, by using the finite element simulation the size of surface displacement of milling workpiece. The results show that spindle speed and axial cutting depth have a significant effect on surface morphology and surface roughness in the experimental parameters range, and the spindle speed has a little effect on surface microstructure. The highest temperature in the cutting zone locates on the toolchip interface at a distance of 001~003 mm from the tool tip. Superficial process quality is the best and the cutting temperature is decreased when the spindle speed is at 9 500 r/min. Simulation results agree with experimental results, demonstrating that the simulation method is correct and effective.